Automatic lathe



E. J. SVENSON April 27, 1937.

AUTOMATIC LATHE Filed Dec. 21, 1951 s sheds-sheet 2 April 27, 1937.

AUTOMATIC LATHE Filed Dec. 21, 1931 8 Sheets-Sheet 3 AP 27 1937- E. J. svENsoN AUTOMATIC LATHE Filed` Dec. 21, 1931 8 Sheets-Sheet 4 April 27, 1937;

E. J. SVENSON AUTOMATIC LATHE Filed Dec'. 21, 1951 8 Sheets-Sheet 5 90 lf2/uente?? vaesj Jz/e/zs/Ja E, J. svENsoN April A27',v 1937.

- vAUTOMATIC LATHE a sheets-sheet s Filed Dec. 21, 1931 Kwzesz J S21/,270307Z ,MQ/@4 A April 27, 1937.

E. J. svENsoN 2,078,697

AUTOMATIC LATHE Filed Dec. 21, 1931 8 Sheets-Sheet 7 @wal/@94 m @5' April 27, 1937. E, J, SVENSON l 2,078,697

AUTOMATIC LATHE Zia/umn Izejfb penso@ Patented Apr.v 27, 193,7r

yUNITED- STATES PATENT OFFICE l 2,078,697 AUTOMATIC LA'rnE Ernest '.I. Svenson, Rockford, lil. Appliclton December 21, 1931, Serial N0. 582,192

38 Claims.

with an improved system of hydraulic control,

whereby the `required amount of time, skill, and effort of a machine operator is materially reduced andthe quality of work produced by the machine is of a 'very high standard.

In lthese days of lineproduction there is a demand for machines which are capable of increased production without impairing the quality of thev work produced, and to this end my invention contemplates the provision of a ma'- v -chine which is capable of performing. heavy duty cutting operations quickly and accurately.

There is also a present demand for material working apparatus or machines which arepartlcularly adapted to eiiectively employ the relatively tough, hard cutting alloys which have been developed in recent years, such as tungsten carbide,-etc., and itis one ofthe objects of my present invention to provide a machine having certain structural characteristics which lend sufi'icient sturdiness or rigidity for rendering the machine particularly adaptable to be equipped with such ctting tcols.- I have found, after operatingv machines constructed in accordance with my invention for several months in actual production work vin the shop, that the surface speed of cutting by using tungsten carbide tools has increased from three to four times over the speed previously obtained by the-use of other conventional machines with which I am familiar. Gonsequently by employing my improved inachine construction a marked increased in pro-l duction is experienced. l

- Another` object ot my present invention is not only to provide a machine ci' rigid and sturdy construction as above set forth,.but one in which the total mass or weight is `considerably reduced, and in which many-of the parts, which in conventional machines are bolted together, are, according to the present invention, formed integral. To this end I propose to provide a novel machine bed comprising ai single casting having a largeportion thereof cored so as lto reduce'its Weight,and toeliminate the usual bolting of ma-V chine frames, I propose to cast the machine bed,

spindle supporting head, etc., in a single integral unit, thereby 'providing an extremely rigid support for those portions of the machine which experience the most severe stresses as, for example, the work supporting spindle, shiftable tool carriages, and the like.

It is another object of my present invention to 5 provide an improved machine, such as an automatic lathe, in which one or more turning tools are employed to remove peripheral stock from a work piece, for example, a piston for internal lcombustion engines, and another tool is adapted 10 to make a facing cut on the work. I also propose to employ one or more grooving tools in combina'- tion with the turning and facing tools, all of said tools being properly timed so that vthe portion ofthe peripheral surface to be acted upon by the 1 grooving tools will be turned prior tov the engagement of the grooving tools with the work, and. the facing tool will complete a portion of its cutting stroke before thegrooving tools act upon the work, whereby to reduce to a minimum the o straining torque experienced by the work piece during the cutting operations. y

My invention also' contemplates a new and improved method of turning a work piece, such as a piston wherein turning and facing tools.V 25 are arranged to Isimu]tar'ieously' actupon the work, the turning tool removingstock from the portion subsequently to be acted upon by onel or more grooving tools. After the turning tool o has removed the stock from the above mentioned portion of the work piece and the facing tool has advanced a suillcient distance to decrease the torque or strain on the piston, growing tools4 begin to cut into the periphery of the work at a speed which is less than the speed of the facing tool, or, in other words, the speed of the grooving tools differs from the speed of the facing tools.

Still another object of my invention is to provide a hydraulic control `for tool carriages and4 the like, which is equipped with an improved main control valve, said valve being automatically shiftablev to control the rate and direction of travel-of a tool carriage with the utmost convenience and accuracy. .o In addition to the above mentioned advantageous characteristics, it is a further object of'v my invention to provide in a hydraulically controlled machine of the type set forth above, a iluid reservoir which is equipped with means f or effecting the gentle return of uid thereto so 'as to positively prevent air from entering the.' rcs-l ervoir, and consequently prevent'airfrom being` trapped within the iluid or oil .which is withdrawn from the reservoir. .55

lIn addition,l I propose to provide in combinationy with the hydraulic system of control for machine tools, an improved pumping device, in which a novel rotary valve is employed, having r structural features which facilitate its lubrica.

tion, and which serve as compensating means when the fluid on opposite sides of the valve experiences variation in pressure.

-A still further object is to provide a valve asv set forth above, which is provided with an arrangement oi fluid ports to prei :nt said valve from experiencing distortion resulting from the extreme iluid pressures to which it is subjected, thereby insuring free running conditions regardless oi' the intensity of the iluid pressure.

The foregoing and numerous other objects and 'advantages will be more apparent from the following detailed description when considered in connection with the accompanying drawings,

wherein- Figure 1 is a plan lviewof an automatic lathe, which is representative of one practical embodiment of my invention, one corner thereof being broken away to enable the insertion of Figures ,25 2 and 3.

Figure 2 is an enlarged detailed vertical sectional view of the mechanism for controlling the positioning of the oscillatory guide bar for the front carriage, said v iew being taken substantially along the line 2-2 of Figure 1.

' Figure 3 is a fragmentary horizontal vsectional view taken substantially along the line 3-3 'of Figure 2. 'Y

Figure 4 is a front elevational view of the machine of Figure 1.

" Figure 5 is a rear elevational view of said machine.

Figure 6 is an end view thereof as viewed from the left end'of Flgure'l. Figure '7 is an enlarged vertical sectional view of the oil reservoir taken substantially along the line 1--1 of Figure 4. A

Figure 8 ,is av vertical transverse sectional view of the machine taken substantially along the line 8 8 of Figure 1.

Figure 9 is a detailed vertical sectional view of the oscillatory carriage which supports the grooving tools, said view being taken substantially along .the line 9 9 of Figure 1, certain portions of the cooperating elements which would not normallyappear in such a section, being shown by dotand.dash lines. i

Figures 10 to 12 inclusive are fragmentary "diagrammatic representations to disclose the various positions occupied by the cutting tools duringtheir cycle ofoperation; Figure 10 disclosing the initial engagement "of the front turn-A ing and rear facing tools with the work; Figure 11 disclosing the partial completion of the cutting action of said tools and the initial lengagement of the grooving tool with the work; and I Figure 12 disclosing the completion of the cutting I turalcharacteristics thereof.`

Figure 14 is a, vertical sectional view of .the main- .control valve and operating mechanism therefor, taken substantially along the line I4-I4 of Figure 13.

' Figure 15 vis a detailed transverse sectional view of the mainfcontrol valve taken substantially along the line ,I5-l5 of Figure 13.

'substantially along the line Il-ifi of Figure 14,

disclosing the relative position of the dogs supported at the lower side of the main control valve.

Figure 18 is a diagram disclosing the general arrangement of. the :duid circuits incorporated within my improved system of' hydraulic control.

Figure 19 is an enlarged central sectional. view of a pressure control device. coupled with the gear pump- Figures 20 to 24 inclusive disclose various views of the unitary casting, which provides the bed, spindle support, etc.; Figure 20 being a plan view;

Figure l21, a front elevational view; Figure 22, an

end view taken from the right end of Figure 21;

'Figure 23, an end view taken from the left end of Figure 21; and Figure 24 being a rear view.

Figure`25 is a central sectional view of one of the high pressure plunger-pumps, disclosing my improved rotary valve construction.

Figure' 26 is a transverse sectional view of the valve structure takensubstantially.along the line 26-26 of Figure 25.

Figure 27 is a similar view taken along the line 2?-21 of Figure 25. Y.

Figure '28 is likewise a similar view taken along the line 28-28 of Figure 25.

Figure 29 is a transverse sectional view of the pump taken substantially along the line 29-29 o! Figure 25;. and

Figure 30 is an elevational view of a`conventional self-expanding compensator, which is representatlve of one type of compensator/adapted to be employed in combination with my improved rotary tapered valve.

Referring now to the drawings,'it will be seen thatslike numerals have been employed to designate similar parts throughout the various figures.

of my'invention disclosed in the drawings.

. General llathe structure' The embodiment of my invention disclosed in y the drawings includes a unitary casting 40, whichy Vin Figures 20 to 24 linclusive is shown detached from any of the lathe elements .which it supports.

- This castingy40 includes. amachine base or bed 42, and formed integral with the bed and sur-- and by so forming thebed, its weight is reduced to a minimum.' In conventional types of ma'-I chines with which `I am familiar, the machine -bed is not formed with a central cored chamber such asmy'chamber 46. Not vonly does the presence of the cored chamber within the bed 42 reduce the weight so as to facilitate the shifting of the machine from 'one position to another, but also reduces the amount of material which is r`e quired to form the base.

Extending upwardly and formed integral with .the base or bed 40 atone end thereof-is a headstock section 48. This section 48 Isl/cast' in one piece with the bed and provides a support for a rotary work supporting` spindle 50. An oil reservoir designated generally by the numeral 52, Figures 4 and 7, is provided within the headstockfsection 48, and mounted upon a cover plate 54 is a pair of plunger pumps 56 and 58. A partition 59 is cast integral with the bed and extends from the forward portion ofV the machine downwardly to the rear portion, Jand at this point communicates with the trough 44. Thus chips, fluid, and the like are directed by-this partition to the trough. Mounted withinthe cored chamber 46 at one end thereof, Figure 5, is a suitable prime mover or electric motor 60, which is connected, through the agency of a suitable chain 62, with a transmission mechanism 64. This transmission mechanism 64 includes a suitable clutch mechanism 66 which serves to control the-delivery of power to the work supporting spindle 50 through suitable gearing shown in Figure 6. I. It will also be lnoted that in Figure 6 the spindle 50 is directly coupled through the agency of suitable gearing with the plunger pumps .56 and 58. Mounted upon the bed 40, Figure 5, is agear pump 68,-

which is continuously driven from the Vtransmission mechanism 64 through the agency of a suitable chain or belt 10. This gear pump 68 is preferably of the type disclosed in my co-pendlng application, Serial No. 430,868, filed 'February 24, 1930, which has since matured into Patent No. -1,912,737,and is adapted to supply fluid for rapid traverse purposes, while the plunger pumps 56 and 58 are preferably of the variable displacement type disclosed in my co-pending application, Serial No. 430,867, filed February 24, v1930, which has since matured into Patent No. 1,989,117. A tailstock 12, Figures 4 and 5, includes a rotary center 14 mounted within a splitbearing 16, said bearing being supported and formed integral with a base .18. rI he base 18 is adiustably supported by the main machine bed v40.

A front tool carriage, denoted generally by the y numeral 60, Iis mounted upon a horizontally and longitudinally shiftable bar 82, which is supported Within the bed `.40, and a rear tool carriage, de-` noted generally by-thenumeral 84, is adjustably mounted upon the rear upper surface of the bed and is adapted to be reciprocated transversely of the axis of the work supporting spindle 50.

vFront toolI carriage The front carriage 80 includes an oscillatory frame or support 86 which is clamped upon the o'scillatory bar 82, Figure 8. A slide 88 is adjustable on the frame 86 toward and away from a work piece l90 disclosed by dot-and-dash lines in Figure 8, and adjustably mounted upon this slide 88 is a tool holder 92 which carries a cutting tool 94. At this point lt should be understood that the spindle is normally driven in a clockwise direction as viewedin Figure 8, so that the cutting force acts upwardly'against. the front tool ,94.

.Movement of the tool carriage toward the work piece is accomplished through the agency of a hydraulic actuator 96, which includes 'a `pis- Juicio bar |84 is pivotedwithin a block |06, Figdresaraanda.. AY'rms biockas adapted to be vertically 'adjusted within a guide |08 `by means of bar |04 with the ltypeofwork piece to be acted upon. If the guide bar |04 occupies a horizontal position when the said piston being coupled with the left extremity kof 'the oscillatory bar82 by means of a piston rodV |20. From the foregoing it will be apparent that the hydraulic actuator 96 serves to move the tool 94 into cutting position with respect to the work piece 90, Figure 8, and the hydraulic actuator I4, Figure 4, serves to impart movement to the tool longitudinally of said work piece. Ob

viously the actuator'96 is designed to move the I front carriage during the cutting operation at both rapid and feeding rates.

includes a slide |22 which is shiftable in a direction transverse to 'the spindle axis by means of a. hydraulic actuator |24, whichiin'cludes, a cylind-er |26, a piston |28, and a pistonrod |30, which is coupled to the rear extremity of the slide |22. The cylinder |26 is formed integral with a frame |32, and this Vframe is adjustably secured to the bed 40, Figure 8. The slide |22 carries a tool holder |34, which supports a cutting tool |36, said tool serving to make a facing cut upon thel work piece (see diagrammatic disclosures in Figures 10 to 12 inclusive).

The rear tool carriage 84 also includes an oscillatory frame |38 which is pivotally-supported by a bar |40 mounted within the frame |32, Figures the cam member |146 engages a roller |50 carried by the frame |38, said frame is swung so asto move the grooving tools |44 intoscutting relation with respect to the lwork piece. It will be apparent that no forward movement will be imparted to the vgrooving tools until the facing tool |38 I has been shifted a predetermined' distance. other words, the rear carriage is so arranged that the facing cut on the work piece is partially completed before the grooving tools are caused to function. This particular arrangement of the rear carriage cutting tools has a very practical application in connection with the turning of pistons'of internal combustion engines. It will be apparent that the greatest torque is experienccd by the piston asthe tool |36 makes its initial facing cut, and that as this tool approachesthe center of the face, the torque or stress upon the piston is materially reduced. By employing my improved structural arrangement. the cutting action of the grooving tools is delayed until the stress to which the piston is subjected as a result of the cutting action of the tools |36 and 94, is materially reduced, thereby overcoming serious difficulties which have here- .tofore been experienced in instances Where the initial grooving and facing cuts have been made simultaneously. 'Ihis feature of the invention will be more readily appreciated from the de. scription which is' to follow. It will be seen that the entire rear carriage 80 may be' shifted longitudinally with respectto the work supporting spindle by merely loosening clamping nuts |52, Figure 1, and then shifting said carriage along ways |54 provided within the machine bed 40.

The slide |22 of the rear tool carriage is me; chanically coupled with a rotary valve control mechanism |56 mounted on the front side of the machine bed. This mechanical coupling includes 0 4a rack |58 shiftable with the slide |22, which meshes with the pinion |00, Figure 9, keyed to a shaft |62. This shaft |82 extends longitudinally of the machine, and is coupled by mmns of be imparted to the gear |06, and a counter-clock vMatin. valve and wise movement to the companion gear |08, as viewed in Figure 13.

rotary control mechanism therefor The rotary valve lcontrol mechanism is designed to timingly control the shifting of a main control valve mechanism designated 'gen-A erally by the numeral 10Flgures 14 to 18 inclusive, which is mounted on the front side of the machine in a convenient position to be actu--` ated by the operator. In order to simplify an understanding of the structural and functional characteristics of the main control valve |10 and the rotary control mechanism |56 therefor, I shall describe these parts in connection with the hydraulic system vof control which governs the ktimed or synchronized movements of the various lathe elementssuch as the tool carriages and the fluid pumps. It will be seen that the valve mechanism .'10 .includes a casing or housing |12, which work piece. Assume further that the valve members |16 and |10 ocoupy'theneutral posisupports a pair of reciprocable valve members |14 and |16, which are coupled by means of a connecting element |18, Figure '13. It will also be seen that the rotary control mechanism |50 includes a plate provided with a Tslot- |82,

which is adapted lto ladjustably receive a plurality-oi' dogs |84,.|86, |88, |90, and |92. This plate |80 is rotatable with the gear |00 and is supported by a stubshaft |04. v

Assume that a' work piece suchv as the cylindrical member 80 shown by the dot-and-'dash lines in Figure 8 andby the full line in Figures 10 to 12 inclusive, is mounted within the spindlev 50, and that thefront carriage 80 occupies its limiting downward position, and the rear carriage slide |22 occupies its rear position.- when the carriages occupy these positions their respective tools 94, |88, and |44 are removed from the tion shown in Figure 13.@and thatl the dogs on the rotary plate |80 also occupy the relative positions shown in Figure 13. The prime mover or y electric motor 80 is now operating and causes the gear pump 60 to be activated. The clutch mechanism 66 is positioned so as to disconnect the work supporting spindle 50 from the prime mover, and thus the plunger pumps 8 8 and 58 amasar arev not activated. The operator shifts a control handie |06, Figure 1, to the left, and said handle being connected with the valve members |10 and |16 by an arm |90, causes'said valve inembers to be shifted to the right, Figure 13.

In this shifted position fluid from the gear pump 88, Figure 18, is directed through a distributor mechanism 200 (later to be described) and thence through a'pipe line 202, Figures 13 and 15, which communicates with a passage 200 of the valve f |14'and a passage 206 of the valve |16. The

valve passage 204 is now incommunication with a pipe line 200, while the passage 200 is closed to a pipe line 2|0, which connects with the valve mechanism. Fluid within the pipe line 200 passes into the lower end of the cylinder |00 of the hydraulic actuator 00, Figure 18, 'thereby causing the piston 00 to be shifted upwardly.

'This results inthe movement of the front tool 9d toward the work piece and in the passage of uid from the cylinder |00 through a pipe line or conduit 2M, a check valve 2id, and a conduit "2te which is connected with a hydraulic actuator .draulic actuator 2|8 passes through a conduit or pipe line 224 into thev rear extremity of the cylinder |20 of the rear tool actuatorIM. 1t will thus be apparent that the shifting of the valve members |14 and |165' to the right, Figure 13, causes the front tool 94 and the rear tool |36to -be moved at a rapid rate into cutting position with rexuxect to the work piece.

The advancement of the rear carriage slide |22 causes the rotary dog support |80 to be shifted in a counter-clockwisedirection, as viewed in Figinto engagement with a nger 220 carried at the lower end of a shaft 229,-'which supports the valve i control handle |96, and this causes the valve .ures 4 and 13. The dog |86 is eventually moved members |16 and |16 .to be returned to the neutral position shown in Figure'13. 'I'he plunger pumps 58 and 58 which were automaticallyactuated upon the establishment of driving connection between thespindle 50 and the prime mover 80, now serve to deliver iluidv at high pressure throughpipe lines .or conduits 230 and 2,32 respectively, Figure 18. This causes the advance ment of the rear tool |96 at afeeding rate across the face of the work piece 90 and the longitudinal travel at a feeding rate of the front tool 94 along the periphery of said work piece. Fluid from the advancing side of the actuator piston |28 is directed through a line or conduit 234 back to the plunger pump 50, and fluid from the advancing side of the actuator piston ||0 passes through a conduit 286, affront carriage control valve 238t and a conduit 240 back to .theintake side foi the pump 88. Itwlll be observed that the dog |92,

upon engaging a iinger 242 carried by a shaft 246 of the valve 208, Figure 13, causes said valve to establish communication between the conduits- Y 288 and 240 at the desired interval s as t'o timingly control the longitudinal travel of the front .tool carriage.

It will be noted, particularly in Figures 13 and 14,- that the rotary plate |80, together with the dogs supported thereby, is detachably supported through the agency of the stub shaft |94.. The dogs on the plate may be supported to effect la predetermined cycle of operation corresponding lwith the particular type of work to be done. If

the machine is to be used for the performance of a different cycle of operation, it has been found advantageous in certain instances to detach the plate and replace it with another one having the dogs thereon positioned in accordance with the new cycle of operation to be performed. This avoids the necessity of employing the operators time to set up the dogs in proper. position each time the machine is used for a different type of work piece. The plates having the dogs properly mounted thereon can be kept in stock and' used whenever occasion demands. This arrangement also enables the machine to be operated by persons not particularly skilled in setting up automatically operable machine tools. A

Attention is now directed to the grooving tools |44 which, during the initial advancement of the facing tool |36, remain stationary. However, when the cam surface |48 of the pivoted cam member |86, Figure 8, carried by the rear tool slide |22, moves into engagement with the roller |50,V the oscillatory frame |38 swings forwardly so as to carry the grooving tools into operative association with the periphery of the work piece. The movement of the grooving tools is timed so, that the tool |36 will have completed a substantial portion of its facing cut before the' grooving tools actually begin to cut. By delaying the operative functioning of the grooving toolsr avoid the necessity of subjecting the work piece to the severe stresses which would otherwise result if said tools were initially brought into simultaneous engagement with the workpiece. Furthermore, the delay in moving the grooving tools permits the front tool 94 to make a peripheral cut across the surface of the work piece previous to the cutting action of the grooving tools. In other words, the front tool 94 removes stock from that portion of the peripheral surface to be acted upon by the grooving tools before said grooving tools startA to cut. Obviously the timing of the movement of the grooving tools will be determined by the nature of the cam surface which engages the roller speed of the facing tool, the speed of said grooving tool in a sense being independent of the speed of the'facing tool, inasmuch as the contour of the cam surface will determinethe speed at which the oscillatory grooving tool carriage is moved.

The feeding stroke of the hydraulic actuators H4 and |26 continues until the dog 88 is moved into engagement with the outer end of a valve member 286, Figure 13. Shifting this valve member to the left against the action of a coil spring 268 effects a sudden establishment of communication between a valve chamber 252 and the fluid reservoir 62. 1n other words, when the valve member 286 -shifts to the left, communication 'oetween a passage 258 and the chamber 262 is closed, and fluid fromthe chamber 252 ows unrestrlctedly through a central valve passage 258,

a radial port 260, and a pipe line or conduit 262.

The sudden release of the iiuid from the chamber 252 enables the normal iiuid pressure within an opposite valve chamber 264 to causethe valve members |14 and |16 to be suddenly shifted to the left. In this position said valve members initiate a flow of fluid in the reverse direction'to the 'hydraulic actuators |24 and ||4. Thus, in

this reverse position fluid from the gear pump 68 passes through the valve ports 204 and 206 v cylinder ||6. It will thus be apparent that the front tool carriage is moved at a rapid rate in a reverse direction, namely, to the right, Figures 4 and 18, and that the rear tool carriage is similarly moved in a reverse direction, namely, to the right, Figure 8. The dog |00 carried by the rotary support |80 eventually engages a finger 210 oppositely disposed from the finger 242, thereby closing the valve 238, and the dog |84 is eventually moved into engagement with a finger 212, Figures 14 and 17, so as to cause the valve members |14 and |16 to be again shifted to their neutral position. This completes the cycle ,lof operation, which may' be repeated by merely shifting the control handle in the manner just described.

, It will be noted that when the valve members ,|14 and |16 occupy their neutral position, uid

from the rapid traverse or gear pump 68 circu- 250 through a longitudinal connecting passageV 282, Figure 15. It will also be apparent that the instant that the valve members |14 andV |16 are suddenly shifted to their reverse position, namely, to the left. Figure 13, the pipe line 208 becomes a return line for the hydraulic actuator 06, Figure 18, thereby enabling the front carriage to suddenly and automatically shift forwardly so as to bring the front tool 94 out oi.

engagement with the work piece.

Due to the fact that the front carriage is mounted upon the oscillatory bar, said carriage will cooperate to reduce the power necessary to lswing the front tool 94 out of engagement with the work piece the instant that the cont'rol valve is shifted into reverse. Thus, the mechanical arrangement of the front carriage is such as to set up less resistance to vreverse fluid action than the rear carriage. The rear tool, due to the mechanical load placed upon the slide resulting from the geared connection which it makes with the rotary dog support |80, and due to the fact that the rear tool carriage is horizontally slidable, the rear tool will remain in contact with the work piece long enough to complete its cut -and will not return until the rotation of the said pumps are connected within closed circuits,

and |15 occupy theirJneutral position 'shown in Figure 13, they render the gear` pump :functionally inoperative for propelling purposes and provide an edective seal for the high pressure circuit. In other words, when the plunger lpumps se and 5t function to propel their respective Ahydraulic. actuatorsat a feeding rate,

the fluid on the discharge side oi the sctuator piston being suicient to charge the plunger pump. In fact, the uid :from the -advancing vrelating to automatic lathes, Serial No. 439,306,

led March 27, 193i), and September 13,1930.

Pleuger pump construction i Particular attention is directed to the struc- Serial No. 481,742, led` ture of the plunger pumps 56' andes, and in this connection special reerencei's mede to Figures 25 to 29 inclusive. The pump, as set forth shove, is oi the general type disclosed in my shove nientioned co-pending application, but incorporates certain novel features which are not shown' in said co-pending application. Both of the'pumps 56 and @t are identical in construction, and therefore the description oi. one will sulce for a description of the other. Each of these pumps includes a central casing idd, an end casing section 2de secured thereto by means of bolts 283, and an oppositely disposed end section or support 2st, Figure 25. lThis support @de houses a plurality of radial reciprccahle plungers or pis- -tons 292, the inner ends of which engage the curved surfaces of pivotedv iingers4 ist. These fingers in turn rest upon/the peripheral surface of a driving ring te@ rotatably supported upon an eccentrically adjustable driving member 2%. By

displacing the center of the ring 2st from the center about which the pistonss radiate, und

Ithen rotating said ring, the pistons are successively urged outwardly to compress fluid in chambers 353i). The eccentric adjustment oi.' the :driving member 288 is controlled by means of suitable adjusting mechanism, which includes .a longitudinally shiftable member 802, which isv provided with e. projection 3M extending into a ber 2da.' This projection 3M liss-inclined with respect to the axis of rotation, and when lorigitudinal movement is imparted to the member M2 .in response to the turning oi e. cap ,308, the driving memherii is laterally shifted within a driving sleeve 308. l. I provide a rotary tapered valve Qliliwhioh is mounted within a. companion bushing SI2, This valve is 'adapted upon rotation to control theflow oi uid toward end'away from the piston chambers '$06. Thus iiuid introduced from the pipe linev disent-.ers a chamber 3M. and from 4this `.lieruber is directed through a central passage' Kilt, lwhich communicates.' with Se. peripheral valve port` 3H'. vThis valve port 318 successively -registers or communicates withradiel ports sie in thepbushing 3|!..i'vhiol:1 connect with limes 326 providedin the support 2st). This peripheral valve port BIB is timed so es to communicate with the piston chambers'tii during the intakev "tewFtheie-Gompanmm pistons 292, while o.l

similar peripheral valve port 322 is timed to communie-ate with those piston chambers son, which aereos? -will he seen that ,sumcient circumferential ltance is provided between the radial ports lllare companion to the pistons experiencing their outer or compressing stroke. Thus `duid under pressure is directed from the passages 320 through a, .peripheral passage S26-in the bushing M2, end this passage in turn communicates With o. rudlal port; 326. Fluid under pressure from these ports tid is directed through the ne ripheral valve port 322 and' into a passage 328,

Figures 25 and 27, which communicates with an annular valve passage' emi. It-shouldbe-noted that this annular passage te@ isl slightly enlerg'ed at the point designatedby the numeral 332, Figure 25, end uid from this annular pas-v sage passes outwardly through the pipe line 231i into the reer extremity of the hydraulic actua` ,tor its. Likewise, iiuid under pressure in the' pump de passes outwardly through the pipe line l .2er to the right end of the hydraunc actuator' y iii! and lower end of the actuator e5. By having the low and high pressure peripheral vvo ports arranged in the manner described.- ebove, I

am ebleto positively preclude the valve from experiencingany distortion which might otherwise result from the subjection ofthe valve to these pressures. yIt will he seen that the high pressure experienced by the valve in the peripherel port 322 is counteracted or neutralized by the uid pressure acting within thesn'nular passage 33d edjscent its' enlarged portion 332, Figures 25 sud 27. 'That is to say, env tendency of the :duid pressure acting on one side oi the valve to cause scid valve to hind or hecome distorted, is' prevented by the neutralization of pressures on opposite sides oi' the valve. This neutralization or balancing 'of the vulve is particularly important when the duid pressure reeches e substantial amount, as, for example, pressures in excess neutralize one another. Thus, for example, the

high pressure uid within the upper threek radial ports MS shown in Figure 26 act downwardly upon the valve, while the' pressm'e in the two I lower radial ports' 319 andthe peripheral port wald act upwardly, thereby eiectlng a. substan- I tially balanced condition. companion recess provided' in the driving mem. y.

Attention is alsodirected -to the fact that by having the low pressure peripheral port )I8 spacedfaxially trom-the high pressure peripheral port all and the comn munlcating annulerl port 380,14the possibilityl o1' *slippae of uid between high-pressure and low @pressure ports isfprevented.' Itwillgbeseen 'inv I Fieure 'dthat' the lllmer three passages orports 33B, as well es the peripheraiport 322, contain high pressure iluid,while the two lower is`Yeinholent circumferential distencefbetween ythe low-pressure norte 326 and the high pressure `ports 32d to mitively prevent any slippage of Huid hetween them. Likewise, in Figur-e126 it Ivocnteiningthe high pressure uidand the ports *als containing the low pressure uid to prevent such slippage. In other words, by axially spacing i .of uve hundred pounds per 'squsre inch. It

that toward the larger.

, radio1 portst contain low pressure iluid. There' l the reduction of slippageis entremelyimp'orf 7'5 i 2,078,697 tant factor in connection with pumping devices 4 i of the type disclosed herein, because, in the ilrst place, fluid slippage causes serious increases in uidtemperatures, and, inthe second place, resuits in a decided decrease in mechanical and propelling eiiiciency. Furthermore, pumps lsuch ltapered valve 3| il.v 'Ihe groove 334 communi- 2i)y cates with the central valve passage 3|6 and as such serves to return fluid which might slowly work its way along the surface of the valve `to the left, Figure 25, back to the central passage 3| 6. It should be understoodv that the tapered construction of the valve is such as to provide a fluid seal within theclosed circuit described above, and positively prevents the leakage or slippage of iiuid longitudinally of the valve toward its larger end to an extent that would impair the efcient functioning of the closed circuit.

To insure proper lubrication of the valve surface extending to the left of the groove 333, Figure 25., I provide the groove 336. This groove-33t is continuously connected through a conduit or pipe line 338 with a passage or port 340 oi' the distributor mechanism 266, Figures 18 and 19.

A similar pipe line or conduit 338 communicatesv with the rotary valve in the pump 56. A portion of the uid under pressure from the gear pump,

.. amount of iiuid pressure within the groove 33t.

`Under normal operating conditions the pressure of the fluid within the groove'. itil@ exceeds the pressure of the fluid in the groove 335, thereby preventing the flow of fluid from the groove 33d to the left, but providing a fluid film along the surface of the valve positioned to the left of the groove 336i, Figure 25. In other words, any tendency for a slight migration of uid along this surface would be from the groove 33S toward the groove 331i. Thus it will be apparent that one of the primary functions oi` the groove 333 isr to present a fluid body under increased pressure at the point where the fluid from the groove 536 might not in some instances provide the required amount of lubrication along the surface of therotary Valve at its larger end.

It should also be understood that the groove 336 provides a compensating means to take care of fluctuations or variations in fluid pressure within the hydraulic system of control. Thus, Vfor example, if the pressure of fluid within the low pressure side .of the system is suddenly increased above the pressure of the uid within the groove 335, said groove will permit a compensating flow or migration of uid from the groove 336 into thegroove 336. Such a suddenincrease in fluid pressure within the low pressure side of the system takes place when the main control and 19.

groove 338 provides a. relief or compensating means. Furthermore, the expansion and contraction of the fluid are similarly compensated for by the kgroove 336.

At this point it should be understood that my particular rotary valve construction with its compensating grooves has a very practical application when used in connection with various types of material working apparatus other than lathes.

For example, a valve of this type used in' connection with a milling machine in which climbing milling is performed has avery practical application. By climbing milling, I mean the milling of a work piece by moving the work piece in the same direction as the, rotation of the milling cutter as distinguished from moving a work piece against the rotation of the cutter. In such instances a pressure may be built up on the advancing side `oi? the actuator pistonwhich is in excess'of the pressure on the trailing side as compared with the opposite conditions which exist in the actuator pistons when used in the machine described in the present application. The compensating groove 33B of the low pressure circuit. and in this vinstance the isv the valve in such instances provides a very practical and eiliciently operable means for bringing about an automatic or self-adjustment of iluid conditions within the high and low pressure V side of the circuits, and, in addition, performs its function of insuring proper lubrication of the i valve at its largerend. In fact, my improved :valve construction equipped with the particular ypumps connected with'machines such as automatic lathes, milling machines, boring machines, and the like. are subjected to substantially continuous operation day in and day out, the problem of insuring a true running fit of the tapered valve over an extended period of time is of the utmost importance.

. To control the fluid pressure within the groove 336, I provide th'e distributing means or mechanlsrn- 26d, which includes a suitable casing 342 which is adapted to be secured within the discharge opening 3M of the gear pump, Figures 18 An adjustable plug 346 is provided within the casing 342 and the shiftingof this plug serves to vary the pressure conditions in accordance with the pressure whichis required within the groove 336. 4Obviously the pressure within the groove 336 is normally above the pressure of the iiuid which passes from the gear pump te through the pipe line 202 into the main control valve lli). 4

In lorder to automatically take up any slight wear in the valve SIU, I have inserted a compensator 'of conventional design indicated generally'by the numeral 338, Figures 25 and 30. The particular type of compensator 348, which I have shownfor the purpose of illustrating one` practical device which may be employed, is ai design commonly referred to .in the tradev as positioned rings 356 and 352, said rings being' provided with cooperating cam -surfaces and a locking pin or key 354.l 'Ihese rings automatically expandas a resultA of means provided within the device for effecting relative rotatlonbetween the rings', and when the separation becomes great` enough to clear the locking pin or key 354, relative rotation ofthe rings will occur so as to take up any slight Wear in the valve. This device is designed to take up less than .0005" axial adjustment. It will be seen that this compensator 358 i is inserted between the valve bushing 342 and an anti-frictionL bearinge 356 .which is clamped by means of a collar 358 mounted upon. the threaded split end of the valve member 340. Obviously other forms of compensator devices for automatically taking up Wear may be employed in combination ,with rotary valves Without departing from the spirit and scope of my-invention. In order to preclude `the introduction of air 'within the fluisbody of the 'mammie system., r

have arranged the reservoir 52 in such a manner as to enable the calm or undisturbed ventrance of fluid within' said reservoir. It Will be apparent from 'Figure 7 that the reservoir 52 includes an I -outer casing 366 and an inner casing 362.gF1uid Which-is returned to the reservoir through a pipe line 364, which connects the reservoir with the valve chamber D, Figure 13, pz'alssesthrough a iixed, restrictedoriiice 366', Figure '7. It will be seen that this orifice is'bell-mouthed on its entrance side and tapers -to a larger opening on its egress side. Fluid passes from this orifice through an inclined conduit 358 and is directed against a substantially conical surface 3N, which has its apex at 3l?. This apex 312 is positioned adjacent the mouth of the inclined conduit 36%, and fluid from theconcluit flows gently along the conical surface t'li, which blends into the side Walls of the inner reservoir, thereby preventing the fluid from being churned cr'swirled to such an extent as to develop' air pockets o r bubbles. In this manner the sudden ingress of the fluid is interrupted .so as to preclude the agitation or stirring of the draulic systems which are. employed for movingy machine tools and the like. A very small amount of air within a circuit' is sulcient to seriouslyy impair 'the operating eiciency thereof. It should be understood that by .employing my hydraulic system of control, I am able to Vgovern the shifting of the tool carriages within a fraction of' a thousandt-h of `an inch, and to accomplish this I have notonly arranged the hyd raulic actuators, pumps, and connecting conduits in such a manner as to provide a closed circuit, but have provided means for positively preventing the introduction of air Within the circuit. Devices with which I am familiar have been employed heretofore to remove air from the system, but my improved arrangement 'mustybe differentiated therefrom inasmuch asI 'propose to preventA the air from initially entering the system, thereby avoiding the necessity of removing air from within the conduits forming a part of the hydraulic system of. control. The mechanism just described for preventing airl from entering the hydraulic system is similar-in some respects actuator tov disengage the clutch,

'aovaeev tothe system set forth in my co-pending application relating to Hydraulic system, Serial No. 456,571, iiled May 28,' 1930, which has since matured into Patent No. 1,985,748 wherein I have disclosed a modified reservoir structure for effecting the calm' entrance of fluid. Experience has shown that the inclusion of air Within a hydraulic system not only causes pulsating effects resulting from the presence of air pockets, but also causes the uid to disintegrate. This is particularly true when air .isl trapped within a fluid, such as oil.v

' Statement of operation i From the foregoing it will be apparent that in operating the above described apparatus, the work piece 90 is mounted upon the work spindle 50. The prime mover or electric motor is activated so as to cause the gear pump S8 to operate. Fluid from the gear pump circulates through the conduit or pipe line 202, the main control valve HD, and the return pipe line 364.

"I'he operator now shifts the 'control handle IBG.

to thev left, Figure V1, thereby causing the valve members lid and H6 to be shifted to the right,

Figure 13. In this shifted position the hydraulic actuator pistons 93 and |28 are shifted so as to effect the rapid movement of the front tool 94 and 4the rear tool 13S toward the work piece. Contemporaneous'ly with the rapid movement of these tools, the hydraulic actuator EIS shifts .the

clutch so as to mechanically connect the spindle 5t and the plunger pumps @6s-and 58 with the prime mover. When the dog. 485 enga ges the linger 226, Figures 14 and 17, the valve members are returned to their neutral position ther i eb cuttmg off the lrapid traverse or gearV pump 6g and .connecting the plunger pumps 56 and 58 in .closed .circuits for imparting feeding movements to the tool carriages. The dog l92 also causes the opening of the valve 238, thereby enabling the front tool carriage to be moved longitudinally of the work piece Thus the front tool g4 Y makes i a peripheral cut across the surface of the Work piece, while the tool |35 makes a facin VWhen the tool i3@ has completed a portiongoi? cutting stroke, the grooving tools |44 are brought 1ntov operative association with the work piece. Upon the completion of the cutting stroke of all the tools. the dog |88 shifts the valve 246, thereby unbalancing the fluid .pressure within th e main control valve Ill). This'causes the sudden .shifting of the valve members |14 and H6 to the left, and throws the hydraulic system of con-'ftrol into reverse. It also causes the clutch thereby. rendering the plunger pumps functionally inoperative for propelling purposes. In this man- .ner the tool carriages are.. returned to their initial starting position, and when the dog |84 er1- gages the finger 212, the valve members |74 and |16 are returned to their neutral position.

Summary vFrom the foregoing description it should be apparent that my invention presents numerous .advantageous structural features.

The manner. in which I have cast the machine bed, headstock, etc., in a single piece-presents a marked improve; ,ment over structures which, to my knowledge, have.' beenemployed heretofore. Not only have I been able to'appreciably reduce the aggregate weight of this-apparatus as compared with conlventional devices so as toenable the convenient lcutting in materials, such as cast iron, etc., but

in. order to render them emcient in operation, a machine of unusual strength and rigidity must be provided. This fact is particularly true in connection with machines of the automatic type,-

such as the automatic lathe described above. It should be noted that by having this unitary or integral casting construction, I eliminate vibrations which, of necessity, present themselves -when numerous parts are bolted or in other ways secured together. Furthermore, by' having my particular unitary bed and headstock construction, I preclude the possibility of misalinement 'of machine parts, which frequently occurs in machines of conventional design during the` shipment from the, point ,of manufacture to the` shop in which the machine is to be used. A very slight loosening or shifting of the supporting elements of the machine is suiiicient to effect a misalinementwhich must, in many instances, be corrected before the machine can actually 'be put into production work. With the idea of overcoming these diiiiculties, I have produced a machine in which the work supporting spindle, for example, is mounted Within a', headstock support formed integral with the unitary bed of the machine. This unitary bed, in turn, supports the carriages, and-therefore I am able to maintain absolute alinement between thetools supported by the carriages and the work piece supported by the spindle.

Particular attention is again directed to my improved method of performing cutting operations upon elements, such as pistons wherein a peripheral and facing cut is taken, and when the facing stroke of therear tool has been partially completed, the grooving operation is begun. In this wayI do not subject the piston to the excessive torque or load which would obviously result in the event that both the facing, turning,

-and grooving tools 'werebrought into simultaneous engagement with the work piece at the beginning of their strokes. As the facing tool moves inwardly, the load or torque experienced by the piston is materially decreased. Furthermore, it is decidedly advantageous to make the peripheral or turning cut by the front tool before the grooving tools are brought into operative association with the work. The above described method enables the production ofparts, such as pistons, to be speeded up, and at the same time maintains extreme accuracyin the work produced.

It should also be clear that my improved hvdraulic system of control has a very practical application in connection with machines of the type described. By arranging the rotary valve in the ,plunger pumps in the manner described, a true running t is continuously maintained. thereby insuring a positive :duid seal, a reduction in wear, and a positive 'prevention of increased fluid temperatures. The rotary valve is maintained substantially in balance with no pressure tending to urge the valve in any particular direction. In

this way the valve may be rotated with minimum power and for an extended period of time. The

automatic means for taking up wear in the valve also contributes materially toward the elcient rod. To take care of this slight volumetric dif- 9 f cooperates with the groove nl in positively insuring proper lubrication of the valve at its larger end, and in compensating for any variations in iluidpressure which frequently result. When. the

pump is employed in the particular type of cir- I cuit disclosed, an increase in fluid pressure within the low pressure side of the circuit is occasioned when the main control valve is shifted so as to instantaneously restrict its ports, and the sudden building up of this pressure is compensated for l0 by the arrangement of the grooves within the valve. The distributor' mechanism provides a f very convenient means for varying the pressure within the groove 318 to accommodate the particular conditions under which the pump is op- 1I erating. Obviously this type of valve is by no means limited for use in connection with circuits applied to lathes, but applies also to a circuit which may be employed in connection with various types of material working apparatus, in which a hydraulic actuator is employed to propel a machine carriage.

It will be noted that the actuator piston i I8 is provided with a'. piston rod i20 lon each side thereof, whereas the actuator piston |28 is provided 2i with a piston rod on only one side thereof. Obviously the volume of iluid displaced from the advancing side of the piston IIB will be equal to the volume of uid received on the opposite side of the piston, whereas the volume of fluid discharged from the advancing,v side of the piston t28, as it moves forwardly, will be slightly greater than the volume taken in on the opposite side of the piston due to the presence -of the piston ab ference, I provide a vent 269, Fig. 13, which is in continuous communication with the conduit or pipe line 26B. 'I'his vent is similar in functional characteristics to the vents disclosed in one of my above mentionedl copending applications,l serial No. 439,306, filed March 27, 1930, and a detailed explanation thereof in the present application is not necessary to aclear understanding of the invention. It will suice to say, however, when a piston is equipped with a piston rod on either side thereof, as shown in the hydraulic actuator H4, a vent, such as the vent 289, is not needed. Both'forms of pistons are-disclosed in the present application vto show that my invention is not limited toany particular form of actuator construction, but is capable of employing pistons equipped with rods on one or both sides thereof. In this connection attention is again directed to the improved fluid ccmpensatingarrangement, with `which the rotary valve 3H) is equipped. n By having the grooves 336i and 338 in the valve, a unique sealing of the fluid is obtained, and by this arrangement any change in iluid volume, due to increased heat, etc., is compensated for, andV the presence of fluid between the grooves positively prevents any uid from leaving the system when said system isV functioning under normal conditions. Attention-is also directed to the fact that capillary action along the surface between the grooves 33t and 33d contributes to the sealing effectiveness of the rotary valve.

"My invention is not limited kto a machine equipped with a single grooving tool, but contemplates the use of a plurality of grooving tools where the nature of the work requires auch a construction. In other words, the front tool carriage is adapted to be equipped with a toolvdiffering in form from the turning tool M. A devicew constructed in accordance with the teachings of my invention may be designed to meet n various problems relating to the grooving of work4 pieces, such as pistons. It has heretofore been the. practice in some instances in the manufacture of pistons to tin the outside diameter of a grey iron piston, and, subsequent to this operation, a

' rcughing and then a finishing grooving cut is made. It will be apparent that a machine constructed in accordance with the teachings of my invention is readily adapted to be employed in l0 such instances.

By causing the returned iiuid to be directed against the conical surface 310 within the iiuid reservoir and then permitting the uid from the inner reservoir to slowly overflow into the outer M reservoir, I am able to positively prevent air from entering the uid at this point. By employing such an arrangement with the sealed or closed uid circuit just described, the conduits thereof will remain free from air pockets. This will enl 20 ablethe tool carriages to be moved Without the 35 tioning of my improved lathe structure have been substantiated by actual work in the eld. Machines constructed in accordancel with the teachings of my invention have been subjected to selvere actual working conditions in the shop and 0 have materially increased shop production.

Obviously numerous changes and modications may-be made in certain of the structural features described above without departing from the spirit and fscope of my invention, said invention being limited only by the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: l

l. In material working apparatus of the class described, a unitary bed including a base formed integral therewith and adapted to rest upon the iioor and having a spindle supporting section formed integral therewith and extending upwardly therefrom, a rotary spinde in said section, a' shiftable carriage mounted upon said 'unitary bed, a chip receiving receptacle formed4 integral with said bed, said receptacle extending upwardly toward and partially housing said carriage so as to provide means for guiding chips away from said carriage and to presenta support for said carriage, means for imparting rotation to said spin dle, and a compartment for receiving said rotation imparting means so as to positionA the same'separate A:from said chip receiving receptacle, whereby to maintain said compartment free from chips and the like, the unitary construction of the bed, chip receiving receptacle and spindle supporting section lending increased rigidity to the entire machine structure.

2. In material working apparatus of the class described, a lmitary bed including Ya base formed integral therewith and adapted to rest upon the ioor and having a spindle supporting section examaca? to provide a support forsaid carriage, a prim mover mounted within said unitary bed for imparting rotationto said spindle, and a compartment forreceiving. said prime mover so as to.

#position the same separate from said chip receiving receptacle, whereby to maintain said compartment free from chips and the like, the integral arrangement of the unitary bed, base, and spindle support lending increased rigidity to the entire machine structure during the cuttingl action of the tools supported by said car,

. carriage shiftably mounted upon said bed,'and a prime mover mounted within said bed for imparting rotation to said spindle, and a` compartment for receiving said prime mover'so as to position the same separate from said chip receiving receptacle, whereby to maintain said compartment free from chips and the like, the integral arrangement of the bed, trough, and spindle support being such as to materiallyenhance the rigidity of the machine structure.

4. A lathe or machine of like nature including an integral bed having an integral chip and uid receiving trough extending laterally thereof and having a spindle support formed integral therewith and extending upwardly therefrom and an integral partition traversing said, bed to direct chips, iluid, and the like to said trough, the

inner portionvof said bed being cored to mate-- `rially reduce the aggregate `weight thereof, a spindle rotatably mounted insaid support, a tool carriage 'shiftably mounted upon said bed, a

prime mover mounted within said bed for imparting rotation to said spindle, and a 'compartment for receiving said prime mover so as to tending upwardly therefrom and formed integral formed integral with said bed, said receptacle Y, extending upwardly toward and partially housing said carriage so as to provide means for receiving and guiding chips away from said carriage and position the same separate from said chip receiving receptacle, whereby to -maintain said compartment free fromchips and the like, the vintegral arrangement of the bed, trough, and'- spindle support being such as to materially en hance the rigidity of the machine structure.

5. In material working apparatus of the class described, a bed, a rotary work supporting spinto make a grooving cut in the peripheral surface oisaid work piece, and power feeding-means for actuating said carriages in a'. manner to cause the peripheral cutting tool to completely mai- Vbefore said groovingl tools engage for cutting action, said power feeding means maintaining a uniform feeding rate during the cutting opera- -tion and permitting said ,peripheral and grooving cuts to be completed simultaneously.

6. In material workingV apparatus ot the class described, a bed, a rotary work supporting spindle mounted thereon, means for imparting rotation to said spindle, a shiftable carriage having v riage for supporting a tool to make a facing cut on said work piece, and avthird carriage for supporting a tool to make a grooving cut in the peripheral surface of said work piece, and power feeding means for actuating said carriages in a mannernto cause the peripheral cutting tool to completely machine the groove cut portion of the work piece before said grooving. tools engage for cutting action, said power feeding means maintaining a uniform feeding Arate during the cutting operation and permitting said peripheral and grooving cuts to be completed simultaneously.

7. In material 'working apparatus of the class described, a bed, a rotary work supporting spindle mounted thereon, means for imparting rotation to said spindle, a shiftable carriage having a tool for making a peripheral cut on a work piece supported by said spindle, a second carriage for supporting a tool to make a facing cut'on said work piece, and a third'carriage for supporting a tool to make a grooving cut in the peripheral surface of said work piece, power means for effecting the actuation of the rst and second mentioned carriages, and power means associ' v ated with one of said carriages for controlling the actuation of the third carriage, whereby a peripheral cut will occur at the grooving position prior to the grooving operation, the peripheral cutting tool serving to completely machine the groove cut portion of the work piece before said grooving tools engage for cutting action, said power means cooperating to maintain a uniform feeding rate during the cutting operation and permitting said peripheral cut and grooving cut to be completed simultaneously.

8'. In material working apparatus of the class described, a bed, a rotary work supporting spindie mounted thereon, means for imparting rotation to said spindle, a shiftable carriage having a tool for making a peripheral cut on a work piece supported by said spindle, a second carriage for supporting a tool to make a facing cut on said work piece, and a third oscillatory carriage for supporting a tool to make a grooving cut in the peripheral surface of said work piece, and power feeding means for controlling the actuation of said carriages'so that the tool supported by the grooving tool carriage will not engage the work piece until the' facing'. tool has completed a portion of its facing cut past the portion of the work piece vto be grooved, said power feeding means maintaining aV uniform feeding rate during the cutting operation and permitting said peripheral and grooving cuts to be completed simultaneously.v c

9. In` material working apparatus of the class described, a bed, a rotary work supporting spindle mounted thereon, meansfor imparting rotation to said spindle, a shiftable carriage having a tool for making a peripheral cut on a work piece supported by said spindle, a second carriage for supporting a tool to make a facing cut on said work piece, and a third carriage `for supporting a tool to make a grooving cut in the peripheral surface of said work piece, power feeding means for effecting the actuation of the first and second mentioned carriages, and a cam mechanism associated with one of said carriages for controlling the actuation of the third carriage, whereby a peripheral cut will occur at the grooving position prior to the grooving operation, said power feeding meansand cam mechanism coopdescribed, a machine bed, a rotary work support ing spindle. tool carriages disposed on opposite sides of the spindle axis, one of said carriages being shiftable longitudinally of the spindle axis for effecting a peripheral cut and the other carriage being shiftable transversely of the spindle axis for eecting a. facing cut, ahydraulic actuator coupled with each of said carriages for effecting the movement thereof, a third tool carriage for effecting a grooving cut in the work piece, and power feeding means for effecting uniform feeding rate of movement of said third carriage after movement has been imparted to the other carriages, whereby to reduce the stress experienced by the work piece during'the cutting y operations. v

11. The method of performing a turning operation upon a rotary work piece which consists in rotating the work piece, moving a tool inwardly across the face of the work piece to remove stock, moving a second tool longitudinally of the work piece to make a peripheral cut and, A

when the tool making the facing cut has completed a portion 'of its facing cut, causing a grooving tool to act upon the periphery of the work piece at a uniform speed which is independent of the facing cut speed, whereby to effect said grooving operation without subjecting the work piece to excessive stresses during the cutting operation.

12. The method of performing a turning operation upon a rotary work piece which consists in rotating the workpiece. moving a tool in-v wardly across the face of the work piece to remove stock, moving a second tool longitudinally cut, whereby to effect said grooving operation Without subjecting the work piece to excessive stresses during the cutting operation.l

13. The method of performing a turning operation upon a rotary work piece -which consists in rotating the work piece, moving a tool inwardly across the face of the work piece to remove stock, moving a second tool longitudinally of the work piece to make a peripheral cut and, when the tool making the facing cut has completed a portion of its facing cut, causing a grooving tool to act upon the periphery of the work piece at a uniform feeding rate, whereby to effect said grooving operation without subjecting the Work piece to excessive stresses during the cutting operation, eecting a substantially simultaneous completion of the grooving and facing cuts, and then moving all of said tools out of engagement with the work piece.

14. In material working apparatus of the class described, a frame, a rotary spindle, an oscillatory carriage mounted on said frame, a pivotal guide bar upon which said carriage is adaptedl and means for adjusting the pivotal point of said v guide bar.

15. In material working apparatus of the class described, a frame, a rotary spindle, an oscillatory carriage mounted on said frame, a pivotal guide'bar upon-which said carriage is adapted to rest, means for effecting the upward movement of the free end of said pivotal guide bar,

` an adjustable block forming a pivotal support for. said guide bar, 'and means Yfor adjusting said block to vary the position of the pivoted i end of said guide bar.

16. In material working apparatus of the class described, aframe, a rotary spindle, a carriage shiftable in a direction transverse to the spindle axis, hydraulic means for effecting the shifting of said carriage, valve mechanism forcontrolling the actuation of said hydraulic means, said Valve including a cylindrical valve member longitudinally shiftable within a casing, uid propellingmechanism for delivering id to said'valve mechanism, a second valve member laterally dis- 20.

posed with respect to thelrst mentioned valve member and adapted in one shifted position to nism, whereby to enable the normal fluid presrelease fluid from one endfof the valve mecha-l nism, whereby'to enable the, normal uid pressure to be acting within the opposite end of Asaid valve mechanism -to suddenly shift the valve member therein, and control means for mechanically shifting said second valve member in timed relation with respect to-the carriage.

17. In material working apparatus of the class described, a frame, a rotary spindle, a carriage shiftable in a direction transverse to the spindle axis, hydraulic means for effecting the shifting of said carriage, valve mechanism for controlling the actuation of said hydraulic means, said-valve including a cylindrical valve member longitudinally shiftable within a casing, uid propelling mechanism for delivering fiuid to said valve actuation of the mechanism, a second valve member laterally disposed with respect to the first mentioned valve member and adapted, in one shifted position to release uid A from one end of the valve mechasure tobe acting withinv the -opposite end of said valve4 mechanism to suddenly. shift the valve member therein, control means for mechanically shifting said second valve member in timed re lation with respect to the actuation of the carriage, and resilient means for normally urging said second valve member in a given direction.

1.8.-In material working apparatus of the class describeda frame, a rotary spindle, a carriage shiftable in a direction transverse to the spindle axis, hydraulic means for effecting the shifting of said carriage, valve mechanism for controlling the actuation of said' hydraulic means, said valve including a cylindricalvalve member longitudinally shiftable within a casing, iiuid propelling mechanism for delivering uid to said valve mechanism, a second valve member laterally disposed with respect to theA first mentioned valve Y* member and adapteddn one shifted position to release fluid from one end of the valve mechanism, whereby to enablethe normal uid pressure to be acting within vthe opposite end of said valve mechanism to suddenly shift the valve member therein, and a control mechanism for mechanically' shifting said second valve member in timed relation with respect to the vactuation of the carriage.

19, In ahydraulic actuator system for pronpeiling machine parts andthe like, va hydraulic actuator including a piston within a cylinder, a low pressure pump forv imparting rapid traverse to said actuator, a high pressure pump for by the tool inthe mst carnage imparting feeding movement to saidactuator,

2' and a distributor mechanism continuously connected withthe discharge side of said low pressure 'pump for delivering a portion of tlie iiuiddischarged by said low pressure lpump to said actuator and the remaining portion to ,said high pressure pump.

20. In material working apparatus of the class described, a frame, a rotary work supporting spindle mounted on said frame, means for impart-v ing jrotation'to'said spindle, a shiftable carriage for supporting a grooving tool, said carriage being shiftable toward and away from a supported Work piece for effecting a grooving cut in the periphery thereof, a secondcanlage for supporting a tool to make a' facing cut onthe work piece, said second carriage being shiftable.to

ward and away from the axis of a supported work piece, and means for timingly controllingsupported work piece for eecting ay grooving cut 5" in the periphery thereof, a second carriage for supporting a tool to make a facing cut on the 35 work piece, said second carriage being shiftable vtoward and away from the axis of a. supported -work piece, and hydraulic actuator system for timingly controlling the movements of said carriages, whereby the grooving tool supported by said first carriage will ytravel at a speed difier- 1 ing from that of the tool supported by the other carriage, and whereby the tool in the first 'cari riage will notv start its' cutting action until the facing tool has completed at least a portion of its cutting stroke.

22. In material working apparatus of the class described, a frame,v a rotary spindle, an oscillatory carriage mounted on said frame, a pivotal guide bar upon which said carriage is adapted to rest, lactuating means for eiecting the upward movement of the free end of said pivotal guideV bar, andabutment means for limiting the upward movement of the free end of said guide bar, said abutment means being secured as a unit with the structure of said actuating means and carried by said frame, whereby to prevent the force exerted by said actuating means from l deiiecting said abutment means with respect to said frame.

23. In material working apparatus of the class described, a frame, a rotary spindle, an oscillatory'carriage mounted on said frame, a pivota-l guide bar upon which said carriage is adapted to rest, actuating means for effecting the upward movement of the free end of said pivotal guide bar, and abutment means including a member extending forwardly of the machine, one extremity of said member mounted v within the frame and the other extremity secured as a unit with the actuating means whereby to prevent the force of the pivotal bar moving into engagement with said abutment means from causing said abutment means to flex laterally with respect to the frame. i 

